Since Pacific oysters (Magallana gigas) were shucked over from Japan to Alaska in 1910, the mouthwatering molluscs have become a cornerstone of the Alaskan mariculture scene. Because of their size, adaptability and taste, Pacific oysters have become the most important oysters on Earth, farmed worldwide. With North American oyster beds in varying stages of fluctuation, Alaska is in a good position to boost its market share.
“Around 15 years ago, we decided to build an oyster hatchery here. None of us had ever done it before,” recalls Sean Crosby, manager of Kachemak Shellfish Growers, a co-op that buys and sells oysters from farmers around Alaska’s picturesque Kachemak Bay.
“The Alaskan shellfish industry was legalised only in 1989, so no one really knew how to grow oysters. The Kachemak Shellfish Mariculture Association was established in 1994 to help develop hatchery protocols and grow-out systems for budding oyster farmers,” Crosby explains.
Pacific oysters don’t reproduce well in cold water, so Alaskan oyster farmers previously had to import seedstock from other states, like Maine or Hawaii.
“Welcome to our hatchery. We provide seedstock for neighbooring oyster farms – around five million finished seed yearly, depending on demand. We kick things off by starting tiny algal cultures, which are just around the size of your pinky. We grow three different types of algae, two diatoms and a flagellate. We then feed them plant food to get the cells to divide and split until the cultures become denser and stronger. When they’re nice and ready, we put them inside aerated five-gallon carboys. Our facility can accommodate around 30 of them. Lastly, they go into mixing tanks to get the proper concentration and density of food per millilitre.”
Once the algal cultures are ready, the hatchery is ready to raise oyster larvae, usually imported from off state. The larvae are reared in controlled nursery tanks, which are fed the various algae mixes, first heated to around 18 °C before being pumped in.
“Our babies eat a lot of algae daily,” Crosby reflects.
After around a month of continuous feeding, the juvenile oysters reach from two to five millimeters in size.
“They start out that you can't even see them, but if fed properly and by using the proper ratios developed in this hatchery, they can really grow fast. We've been doing this for years and it works,” Crosby explains.
© The Fish Site / Hatch Innovation Services
The juveniles are then sent out to FLUPSYs or oyster rafts and farms statewide, where oyster farmers begin three to four years of often-backbreaking work, caring not just for oysters – but the various bags and stackable cages that hold them in place and protect them from predators like otters.
Around half the oysters will make it to maturity and can be sold for $1 apiece and up.
Aside from the hatchery, Crosby helps oversee a thriving one-acre oyster farm, plus a cooperative that buys and sells oysters from around Kachemak Bay.
“The cooperative sells nearly 200,000 oysters yearly – almost all to walk-in customers or via online orders. The simple addition of an oyster bar at our office drove up sales,” he explains.
There’s definitely money to be made in oysters, but Crosby warns that it takes a special, hardier breed of farmer to succeed in Alaska.
“There are quite a few challenges for mariculture here, starting with the weather. It’s cold. Our growing season is probably two-thirds of what it is down in the lower 48 states. The distances here are far greater. There’s rarely any access by truck, whether you’re farming oysters or other products like kelp. What we do have going for us is quality, which commands better market prices. The quality of the oysters we produce in Alaska is just outstanding. You should all try it.”
*This article is part of a project commissioned by the SEC to highlight the region's mariculture sector. To learn more about the sector visit https://alaska.seaweedinsights...
© The Fish Site / Hatch Innovation Services
